Apparatus for stranding fibers with reversing twist



Feb. 11, 1969 A. UNGER ETAL APPARATUS FOR STRANDING FIBERS WITH REVERSING TWIST Filed Feb. 8, 1968 United States Patent .7

US. 'CI. 57-59 11 Claims Int. Cl. D011] 7/02, 13/26; D07b 3/02 ABSTRACT OF THE DISCLOSURE An apparatus for stranding fibers with reversing twist is disclosed wherein a reeling store can rotate reversibly in the standing axis. Fibers are stranded and wound onto the store with a twist, the resulting loops are moved along the store axis until taken up through unwinding. The strand is wound and unwound on opposite ends of the store and in opposite directions, both of them are peri0dically reversed. The strand is axially movably arrested on the store at the points of reversal.

The invention relates to a device for continuously stranding individual fibers or filaments such as wires, etc. to form a single strand with reversing twist. The device basically is composed of a stranding element, an oscillating store, and a withdrawal portion.

It is known to strand fibers with reversing twist by means of an equipment which includes a rotatable store. Known equipment of this type is, for example, described in United States letters Patent 3,169,360. Here, the individual fibers or filaments to be stranded are withdrawn from stationary supply reels or spools, fed through a stationary apertured disk, run through a stranding head and then fed to a store. By rotating the store about its longitudinal axis one obtains the desired twisting. The strand composed of the strung fibers and filaments is then withdrawn from the system by means of a stationary device and finally wound upon a storage storing drum.

The particular store used in this known equipment is comprised of two parallel rolls, drums or the like positioned vertical to the axis of twisting and mounted in a cradle which is rotatable on the longitudinal axis, and over which the strand is run in a block and pulley type member. Stranding is carried out in such a manner that individual fibers, after having passed through an apertured disk, are wound loop next to loop onto the drums or the like in the cradle and in a block and pulley manner and until the store is filled so that the beginning of the strand appears at the exit of the store. The fibers are twisted either at the entrance or the exit of the store. When the cradle rotates, twisted fibers are wound on the store, while previously not twisted fibers are twisted as they leave the store. When the store is filled with fibers twisted at the entrance, the cradle stops, and the latter fibers are withdrawn from the store while the store is filled from the other side with untwisted fibers. When the store is filled with untwisted fibers, the cradle is rotated again etc. The direction or sense of the resulting twist of the strand depends on whether the fibers were twisted at entrance or exit side of the store. It follows that the distance of the reversing point is directly dependent upon the storage capacity of the store. It is desirable to strand fibers with reversing twist where the direction between the reversing points of the strand is relatively large. This is so because after cutting the strand into portions of desired length, each such portion should not include a twist reversing 3,426,519 Patented Feb. 11, 1969 point. Otherwise, particularly if the distance between the reversing points is relatively small, for example 50 meters or the like, a considerable amount of waste undesirable quantity is produced.

It has been tried to increase the storage capacity in the known stranding equipment, for example by increasing :the size of the drums or sheaves employed or by increasing the distance between the drums or sheaves. The stor- 'age capacity could in fact be increased in that manner, however, it was found that the masses to be moved, i.e., the weight and momentum of the store required to be rotated increase in accordance with increase of desired storage capacity, so that the oscillating frequency of the cradle has to be reduced which in turn reduces operating speed of the device as a whole. The problem, i.e., the increasing of the storage capacity without increase of movable mass in comparison with known equipment is obtained in accordance with the present: invention.

The stranding device in accordance with the present invention includes a store oscillatorily rotatable on the stranding axis, and guide means on opposite sides of the store, one of which is on one side of the store to strand the fibers and winds the resulting twisted strand onto the store in cooperation with the rotating store, while on the other side of the store the other guide means in cooperation with the store as rotating at any instant unwinds the strand at least without completely untwisting it. At least one of the guide means rotates on the axis, and they reverse in synchronism to each other and with the store. The loops as sequentially wound upon the store are moved thereon from one side to the other for unwinding therefrom. Whenever guide means and store reverse rotation, the reversing point is azimuthally fixed on the store but moves axially with the loops towards the other side for unwinding.

As the store is positioned for rotation on the stranding system axis, a very large capacity can be chosen without unduly increasing the mass. Moreover, the coaxial arrangement of guide means and store reduces the size and weight of movable elements below the known constructions. Also, the strand does not change direction as often so that, for example, handling of copper fibers and a resulting reduction in electric conductivity is avoided.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention, the objects, features and advantages thereof will be better understood from the following description taken in connection with the accompanying drawings in which:

There is shown schematically and partially in side elevation a stranding apparatus in accordance with the preferred form of practicing the invention.

Proceeding now to the detailed description of the drawings, the figure shows individual filaments or fibers originating in a suitable source or unwound from reels and entering the stranding apparatus illustrated from the left of the drawing. The completed, twisted strand 9 leaves the apparatus towards the right in the drawing for a suitable take-up device for further storage, such as a drum or the like; source of the fibers and destination of the strand art not further shown.

The individual fibers or filaments 90 enter the strand ing apparatus through a fixed aperture-disk 4 and run towards a guiding and stranding assembly 2. Assembly 2 includes a stranding sheave or pulley 16 1 which gathers the fibers or filaments in the system axis 13 and leads a strand 9 towards an aperture 24 in a first guide member 21 pertaining to assembly 2, which is capable of rotation around the axis 13 for twisting the fibers to form the strand 9. In the preferred form, member 21 is a disk and its guiding aperture 24 is located rather close to the periphery of disk 21. Pulley 161 is journaled in a bearing arm 163 which is mounted on disk 21 eccentrically to system axis 13. As disk 21 rotates, the pulley 161 remains tangent to axis 13 at the point of gathering the fibers '90.

The strand 9 passes axially through aperture 24 and is redirected by a guide member to be wound upon a temporary store 10 in sequential loops. The store 10 is constructed and operated so that these loops extend around stranding axis 13 as the axis of winding. Through a mechanism more fully described below, the individual loops as wound onto store 10 move axially, and, in the drawing, to the right towards an assembly 3 which is instrumental for unwinding. The strand is thus wound onto store 10 which accumulates strand by moving the loops from one side to the other. Thereafter, strand is withdrawn from the store 10 through a guiding nose 35 adjacent an aperture 34 of a second guide disk 31 of the assembly 3. Disk 31 is rotatably mounted and positioned coaxially to the disk 21. A pulley 162 is journaled in a bearing member 164 which, in turn, is mounted to disk 31 in a manner analogous to the mounting of pulley 161 by bearing arm 163 onto disk 21. Pulley 162 guides the string 9 from aperture 34 in disk 3 back into the stranding axis 13 from which it can be withdrawn by the takeup device to the right of the drawing (not shown).

The store 10 includes at least two endless belts 5 and 6. Belt 5 is wound around two rolls 7 positioned in parallel relation to each other but transverse to stranding axis 13. The rolls 7 are placed in that position along axis 13 so that belt 5 can travel predominantly in direction parallel to axis 13. The rolls 7 rotate in such a manner that the side of the respective belt portion facing away from axis 13 has direction from disk 21 towards disk 31. The second belt 6 is wound upon a pair of rolls 8 in an analogous manner. The belt 6 moves also in a manner that the respective outer portion facing away from axis 13 travels from the vicinity of disk 21 towards disk 31.

In case of a two-belt arrangement, as illustrated, they are positioned symmetrically to axis 13. Moreover, each of the belts is positioned so that the center line through the respective belt is located in a radial plane running through the stranding axis 13. One of the rolls of the roll pair 7 and one of the rolls of the roll pair 8 are driven respectively through drives 71 and 81, so that the belts 5 and 6 obtain the desired motion. Belts, rolls and driving elements are mounted in a frame having elements 72 and 82 journaled for rotation about axis 13.

These elements 5, 6, 7, 8, 72 and 82 together constitute the store 10, whereby particularly the respective outer portions of belts 5 and 6 offer surfaces upon which strand 9 can be wound. By operation of nose 25, strand 9 can be looped around the storage area of store 10 as defined by the two belts 5 and 6, provided there is relative rotary motion between guide element 21 and store 10 about axis 13. A loop is thus formed onto and around those outwardly facing portions of belts 5 and 6 which move away from guide disk 21. Thus, by operation of the belts such a loop is transported, in the drawing from the left to the right. After having traversed the axial length of the store the looped strand can be withdrawn from the store, particularly through the aperture 34 of guide disk 31.

In the case of a two-belt arrangement, the loops wound are rather oval, depending on the width and deformability of the belts. One can see that the storage capacity of store 10 can be enlarged if several, even many, of such belts are used and arranged around the stranding axis to approximate the surface of a cylinder. Another factor determining the capacity of store 10 is, of course, the length of the belts 5 and 6. Still another factor determining the capacity of the store is the winding speed in relation to the speed of the belts, as that determines whether the loops are close to each other or far apart.

Speed control here permits change in the storage capacity.

Guide disk 21 is, for example, peripherally provided with a gear meshing with a pinion 22 which is driven through a gear 23 by a reversible motor 41. Additional pinions (not shown) may be positioned around the periphery of disk 21 to rotatably mount disk 21 for rotation on axis 13. The additional pinions are merely follower gears and they are respectively journaled in fixed bearings. The frame as composed of frame elements 72 and 83 is likewise geared (gear 73) t motor 41 to cause store 10 to rotate about axis 13, but at a rotational speed different from the speed of disk 21. The value of the speed differential determines the winding speed, i.e., the number of loops wound per unit time. That speed, of course, depends on the speed with which the fibers are supplied. For a given sense of direction of the relative rotation (speed differential) between assembly 2 and store 10, strand 9, after having passed through the aperture 24 or disk 21, runs over guide nose 25 and is wound upon the store 10 as composed of the two belts 5 and 6. The input device 2 of store 10 and as composed of guide disk 21 with attachment causes the fibers to be twisted so that sequential loops as laid onto the store 10 form a continuous twisted strand. The direction and length of the twist depends on the direction and speed of rotation of the input device 2 as rotating about axis 13.

Each loop as it has been wound upon belts 5 and 6 around axis 13 by cooperation of the rotating disk 21 and store 10 is transported by the two synchronously running belts 5 and 6 away from disk 21, and towards unwinding assembly 3. Unwinding from the store results from relative rotary motion about axis 13, between store 10 and assembly 3 and at a direction equal to the direction of relative rotation between store 10 and assembly 2 during the previous winding of the particular loop now to be unwound.

In the general case then, disk 31 of assembly 3 must be capable of rotation. Thus, guide disk 31 is likewise provided for the speed differential between assembly 2 with a pinion 32 which, in turn, is driven by motor 41 through a gear assembly 3. If twist reversing were not provided for the speed differential between assembly 2 and store 10 would be equal to the speed differential between assembly 3 and store 10 throughout, and these differentials would have the same direction as to the strand 9, because winding and unwinding of any loop requires the same direction of rotation for the two processes.

It has to be observed now that, in general, the unwinding process resulting from a speed differential between guide disk 31 and store 10 can be obtained by rotation of disk 31, relative to store 10 or by an oppositely directed rotation of store 10, or by a combination of both; whenever disk 31 rotates for unwinding, the assembly 3 may also tend to untwist the strand, whereas unwinding by rotation of store 10 relative to disk 31 does not untwist the strand. Special precautionary steps could be taken to prevent device 3 from providing any twist upon the strand (that may untwist it). However, the desirability of providing a reversing twist lends itself to a control of producing a permanent twist in which by proper selection of the operating values unwinding can be carried out without untwisting even though the unwinding mechanism is capable of twisting or untwisting.

In accordance with the invention the stranding operation is to provide a reversing twist. This means that after the store 10 has been filled to capacity under the existing conditions, the sense of winding, i.e., the direction of the rotational speed differential between assembly 2 and store 10, is reversed by reversing the rotation of motor 41. It follows, therefore, that store 10 is filled first with loops wound thereon in one direction; after reversal the loops are wound in the opposite direction, thereafter again in the first direction, etc., and in alternating sequence. For example, first in right hand sense and then in left hand sense; again in right hand sense, etc. If, for

example, gear box 23 provides a relative high speed to assembly 2 and box 73 a lower speed for store 10, mere reversal of motor 41 at otherwise constant speed suffices to merely reverse the direction of winding and sense of twisting without change of the winding speed and of the extent of twisting produced. In other Words, both directions are regarded as equivalent and produce equal results except for the direction of winding and twisting.

With each reversal of winding and twisting there is a reversing point on the store, which, pursuant to the axial movement of the belts, moves from the left hand side to the right hand side and at the same rate with which the loops themselves move. Such a point in which the sense of winding and twisting of strand 9 reverses is not stable, per se, as to azimuth, but it has to be fixed azimuthally in relation to store 10 and its axis. Without fixing the points of reversal, assembly 2 would cause unwinding of that which has just been wound.

The reversing points are, for example, established by providing one of the belts, for example, belt 6, with two noses or posts such as 11 and 12 and which are positioned in diametrically opposed relation on the belt. If reversal of winding takes place just when one of the noses 11 or 12 passes around the particular roll of pair 8 which is close to disk 21 and begins to travel along the outer travel path of belt 6 towards unwinding assembly 3, strand 9 is thereby looped around that nose, 11 or 12, as disk 21 and store 10 reverse. It will be appreciated that accurate synchronization of the position of the noses 11 and 12 and of the timing of reversing motor 41 is desirable for purpose of providing eflicient operation. Automatic equipment can be used for this purpose, but one can also have a skillful operator observe the position of the noses and to manually control the reversing. Some slack is permitted as long as the reversing loop of the strand will soon be impeded by the approaching nose, be it 11 or 12.

Inasmuch as noses 11 and .12 and thus the reversing points are diametrically positioned on the belt, it follows that winding and unwinding operations are, so to speak, out of phase by 180. If a plurality of loops have been wound on the store after a reversal took place, then the unwinding has to reverse at the time that loop arrives, to subsequently unwind in the same direction as that particular loop and the following ones have been wound. On the other hand, at the same time that particular loop (preceded by a reversing point) arrives at the unwinding side, the winding reverses again. Thus, winding and unwinding are always in opposite directions in relation to the store 10, and both processes are reversed at the same time. Inasmuch as the speed differentials are reversed and run always in opposite directions, gear 33 can, in fact, be coupled to motor 41 and causes reversal of disk 31 simultaneously with the reversal of disk 21 and store 10. Moreover, gear 33 is constructed so that the speed differential between assembly 3 and store 10 is, at any instant after a reversal, equal in magnitude to the speed differential between store 10 and assembly 2, but oppositely directed as far as the resulting winding and unwinding process is concerned. Thus, assembly 2, for example, may run at a high speed (and oscillate in between two high speed values), store 10 may run at a lower speed (i.e., oscillate between two such lower values), but always at the same direction. Assembly 3 then may run at a very low speed (oscillate between two such values) and, depending on the numerical values chosen, at the same or the opposite direction as assembly 2 and store 10 at any instant. This, in turn, permits the providing of a speed differential between assemblies 2 and 3 themselves, as far as operating on any particular loop is concerned, i.e., under consideration of the phase shift between winding and unwinding of any particular loop, which phase shift is equal to the period between reversals. That speed differential is instrumental in producing a resulting twist on the strand.

The relationship can readily be understood if one considers the special case in which store 10 rotates at half the speed of assembly 2; assembly 3 does not rotate at all in this case. The assembly 2 thus causes twisting and the speed differential between store 10 and disk 21 causes winding of strand onto store 110. The speed differential between store 10 and disk 31 causes the loops to be taken off store 10 while assembly 3 neither twists nor untwists the strand leaving the system; two complete twists per loop on the store 10 are obtained in this case.

If store 10 does not rotate at all, assemblies 2 and 3 would rotate at oppositely equal speeds, so that the strand as twisted could be completely untwisted, which is obviously an undesirable situation. Also, equal speeds for assembly 2 and store 10, or store 10 and assembly 3, are excluded operating states because they respectively represent absence of winding or unwinding. Thus, by suitably adjusting and selecting the rotational speeds and direction of rotation of assemblies 2 and 3 and of store 10 around stranding axis 13 and within the permissible range, the degree of twisting for strand 9 through the device can be adjusted. Adjustment and selection of the speed of the belts is instrumental in selecting the length of the strand between two points of twist reversing. Adjustment of the speed differentials between assemblies 2 and 3, on one hand, and store 10, on the other hand, determines winding speed which, in turn, permits adjustment of the system to the desired passage speed of the strand 9 as determined by the flow rate of fibers into the system. Gears 23, 33 and 73 may be adjustable to obtain the desired speed and speed relation values. Gearing is understood here in a general sense'and includes planetary drives, friction drives, rolls, etc. In lieu of a reversible motor a reversing clutch could be interposed between gear boxes 23, 33 and 73 on one hand, and the motor 41 on the other hand, the motor then running con tinuously at constant speed. Disks 21 and 31 could be substituted by disk segments, arms or the like.

The invention is not limited to the embodiments described above but all changes and modifications thereof not constituting departures from the spirit and scope of the invention are intended to be covered by the following claims.

We claim:

1. Apparatus for stranding fibers at reversing twist, comprising:

first rneans for accumulating strand in loops about a particular axis, and being disposed for rotation about the axis;

second means disposed coaxially to the first means for rotation about the axis for receiving fibers to be stranded and for twisting the strand about the axis upon rotation on the axis and causing strand to be wound on the first means;

third means coupled to the first and second means for obtaining rotation of the first and second means at a speed differential to obtain winding: of twisted strand loops onto the first means;

fourth means disposed coaxially to the first means and for rotation about the axis for receiving strand unwound from the first means at a speed differential between the first and fourth means, there being a speed differential between the second and fourth means to obtain a resulting twist in the received strand;

fifth means coupled to the third means to obtain alternatingly reversing, oppositely directed speed differentials between the first and second means, and the first and fourth means; and

means operatively coupled to the first means for preventing unwinding of strand from the first means by the second means upon reversal of the direction of the speed differential between the first and second means by operation of the fifth means.

2. Apparatus for stranding filaments at a reversing twist comprising:

first tmeans disposed for rotation about an axis for storing loops of a strand, each of the loops moving axially from an input portion to an output portion of the first means;

second means disposed rotatably about the axis of sequentially winding loops of fibers onto the first means at the input portion thereof and including means for stranding the fibers;

third means disposed rotatably about the axis for sequentially unwinding loops of the stranded fibers from the output portion of the first means;

fourth tmeans coupled to the first, second and third means for providing rotation to the first, second and third means, at rotational speed differentials between them to obtain the sequential winding, unwinding and twisting of the strand, and including means for alternating the sense of winding and unwinding for thereby alternating the direction of twisting of the fibers; and

means for azimuthally arresting the points of reversion of loop winding on the first means as resulting from a change in the sense of direction of winding as provided by a change in direction of the speed differential between the first and second means, the point of reversion arresting moving axially from the input portion to the output portion of the first means.

3. Apparatus as set forth in claim 2, the fourth means providing at any instant speed differentials between the first and second means and between the first and the third means.

4. Apparatus as set forth in claim 2, the first means including means for transporting the loops as wound sequentially from the vicinity of the second means towards the third means.

5. Apparatus, as set forth in claim 2, the first means comprising a plurality of endless belts for moving axis parallel to each other and to said axis, the loops being wound over the belts and moved by the belts from the input portion to the output portion, and means providing such belt movement including a pair of rolls for each belt, positioning the belt so that the center line of the belt traverses a radial plane through the loop axis.

6. An apparatus, as set forth in claim 5, the fifth means comprising a pair of posts on one of the belts equidistantly spaced thereon.

7. An apparatus, as set forth in claim 2, including a first roll journalled in the second means, rotating therewith but rotating itself at any instant in a radial plane in relation to the axis to maintain a tangential position to that axis, the first roll guiding the fibers towards the second means, and a second roll on the third means disposed analogously on the third means as the first roll is on the second means for axially guiding the strand out of the apparatus.

8. .An apparatus, as set forth in claim 2, the second and third means comprising discs, each having a peripherally located aperture, and each including a nose for guiding the strand between the first means and the respective aperture.

9. Apparatus for stranding fibers at reversing twist, comprising:

first means for accumulating strand in loops about a particular axis, and disposed for rotation about the axis;

second means disposed coaxially to the axis for guiding strand towards the first means for twistingly winding of the strand onto the first means;

third means coupled to the first and second means for providing rotational speed to at least the first means to obtain a rotational speed differential for obtaining the twisting Winding of strand onto the first means;

fourth means disposed in relation to the first means for receiving strand from loops wound on the first means;

fifth means coupled to the first and fourth means fior providing a rotational speed differential between the firs-t and fourth means oppositely directed to the speed differential between the first and second means;

means coupled to the third and fifth means for alternatingly reversing the sense of direction of the speed diiferentials in alternating phases; and

means operatively coupled to the first means for preventing unwinding of strand from the first means by the second means upon reversal of the direction of the speed differential causing the winding.

'10. Apparatus as set forth in claim 9, the speed difierentials being oppositely equal at any instant, the phases having duration equivalent of the period between winding and unwinding of any loop by operation of the first, second and fourth means.

11. Apparatus for stranding fibers at reversing twist, comprising:

first means for accumulating strand in sequential loops about a particular axis, the first means disposed for rotation about the particular axis;

second means disposed in coaxial relation to the first means fior twisting-1y winding loops of a strand onto the first means;

third means disposed in coaxial relation to the first means for receiving loops unwound from the first means;

fourth means coupled to the first, second and third means for reversing direction of winding, twisting and unwinding; and

means positioning the strand on the first means upon reversal of winding to inhibit unwinding of strand by the second means and a proximately until the portion of a strand wound at time of reversal is received by the third means.

References Cited UNITED STATES PATENTS 2,790,299 4/ 1957 Gillis et al 57-64 XR 3,169,360 2/ 196 5 Conrail et a1 57-34 3,365,871 1/1968 Schatz et a1 57-59 3,367,097 2/ 1968 Menasofi 57-34 3,373,549 3 /1968 Shaw 57-34 3,373,550 3/1968 Symonds 57-34 3,385,046 5/1968 Sch-atz 57-60 JOHN PETRAKES, Primary Examiner.

U.S. O1. X.R. 

